In the photolithography process, which is one of the processes for manufacturing micro-devices such as semiconductor devices or liquid crystal display devices, an exposure apparatus that projects a pattern formed on a mask onto a photosensitive substrate is used. Such an exposure apparatus has a mask stage that supports a mask and a substrate stage that supports a substrate and, while successively moving the mask stage and the substrate stage, projects an image of the pattern of the mask onto the substrate via a projection optical system. By the way, some of such exposure apparatuses include two stages that are movable independently of each other on the image plane side of the projection optical system. Further, in manufacturing micro-devices, miniaturization of the pattern formed on a substrate is required in order to make such micro-devices high-density ones. To address this requirement, it is desired that the exposure apparatus have a still higher resolution. As a means for realizing such a still higher resolution, such a liquid immersion exposure apparatus as disclosed in the patent document 1, below, in which the space between the projection optical system and the substrate is filled with a liquid to form a liquid immersion region, and an exposure process on the substrate is performed via the liquid of the liquid immersion region. Patent Document 1: International Publication WO 99149504 pamphlet.